Orbital's Second Cygnus ISS Resupply Flight Postponed - NET July 1

(Dulles, VA 9 June 2014) – Orbital Sciences Corporation (NYSE: ORB), one of the world’s leading space technology companies, today announced that it has updated its Antares launch schedule for the Orb-2 mission to a date no earlier than (NET) July 1, 2014. Orb-2 is the second of eight cargo resupply missions to the International Space Station under the company’s Commercial Resupply Services (CRS) contract with NASA. The new launch schedule reflects the timing of the investigation into the cause of an AJ26 engine failure that occurred in late May at NASA’s Stennis Space Center during customary acceptance testing. All other elements of the Orb-2 mission are prepared to move forward, including the Cygnus spacecraft, which is fueled and, except for late-load cargo, is packed with its manifest of ISS cargo.

The engine that failed was designated for use in a 2015 CRS mission and was undergoing hot fire testing that all Antares AJ26 engines are subject to in order to ensure nominal performance and acceptance for use in Antares missions. The investigation into the failure is being led by the Antares main stage propulsion supplier, Aerojet Rocketdyne, with Orbital and NASA engineers also supporting the effort. Once the investigation team reaches the point in their process that they can clear Antares to launch the Orb-2 mission, a targeted launch date will be established. For now, NET July 1 is simply a planning date. Please check back here for further updates.

About Orbital

Orbital develops and manufactures small- and medium-class rockets and space systems for commercial, military and civil government customers. The company’s primary products are satellites and launch vehicles, including low-Earth orbit, geosynchronous-Earth orbit and planetary spacecraft for communications, remote sensing, scientific and defense missions; human-rated space systems for Earth-orbit, lunar and other missions; ground- and air-launched rockets that deliver satellites into orbit; and missile defense systems that are used as interceptor and target vehicles. Orbital also provides satellite subsystems and space-related technical services to government agencies and laboratories. More information about Orbital can be found at http://www.orbital.com. Follow the company on Twitter @OrbitalSciences.